Oil-soluble esters of monocarboxylic acids and polyhydric or aminoalcohols

ABSTRACT

ESTERS OF MONOCARBOXYLIC ACIDS AND POLYHYDRIC OR AMINOALCOHOLS USEFUL AS ADDITIVES FOR LUBRICANTS AND FUELS. THE ESTERS OF A MONOCARBOXYLIC ACID HAVING AT LEAST ABOUT FIFTY ALIPHATIC CARBON ATOMS EXCLUSIVE OF THE CARBOCYL CARBON ATOM AND POLYHYDRIC ALKANOLS CONSTITUTE PREFERRED EMBODIMENTS.

United States Patent OIL-SOLUBLE ESTERS OF MONOCARBOXYLIC ACIDS ANDPOLYHYDRIC OR AMMO- ALCOHOLS John Fred Bork, Timberlake, Ohio, assignorto The Lubrizol Corporation, Wickliffe, Ohio No Drawing. Continuation ofabandoned application Ser.

No. 20,800, Mar. 18, 1970, which is a division of application Ser. No.712,627, Mar. 13, 1968, now Patent No. 3,542,678. This application Nov.22, 1971, Ser. No. 201,156

Int. Cl. C07c 69/32, 93/16; C01m 1/24 U.S. Cl. 260-4045 Claims ABSTRACTOF THE DISCLOSURE Esters of monocarboxylic acids and polyhydric oraminoalcohols useful as additives for lubricants and fuels. The estersof a monocarboxylic acid having at least about fifty aliphatic carbonatoms exclusive of the carboxyl carbon atom and polyhydric alkanolsconstitute preferred embodiments.

This is a continuation of my earlier filed copending application Ser.No. 20,800 filed Mar. 18, 1970 now abandoned which, in turn, was adivision of earlier filed application Ser. No. 712,627 filed Mar. 13,1968, now U.S. Pat. 3,542,678.

This invention relates to novel oil-soluble compositions of matter andto fuels and lubricants containing these compositions. In particular,the invention is concerned with esters of high-molecular weightmonocarboxylic acids with polyhydric alcohols or amino alcohols and tofuel and lubricant compositions containing these esters.

The esters of the invention impart sludge-dispersing properties tolubricating oils such as crankcase lubricating oils used in internalcombustion engines. The esters are effective at temperatures lower thanthat at which metal-containing basic detergents are effective. This isparticularly advantageous in the operation of engines for short periodsof time, for example, in the typical stop-andgo driving of automobiles.Under such operating conditions, the engine oil does not reach optimumtemperatures and the metal-containing detergents such as the basicalkaline earth metal petrosulfonates are not completely effective. Infuels, the esters serve to reduce the formation of carbonaceous depositswithin the engine such as those which accumulate on the valve points. Inaddition, incorporation of the esters into the fuels promotescleanliness of the fuel system, i.e., the carburetor, fuel lines, andthe like.

In accordance with the foregoing, it is a principle object of thisinvention to provide novel esters.

A further object of the invention is to provide oilsoluble esters ofhigh-molecular weight monocarboxylic acids.

An additional object is to provide fuel and lubricating compositionscontaining the esters of the invention as additives.

These and other objects of this invention are accomplished' by preparingan oil-soluble ester of a carboxylic acidan'd an alcoholcharacterized bythe presence within its structure of '(A) a carboxylic acid moiety whichis the acyl residue of a monocarboxylic acid having at least about fiftyaliphatic carbon atoms and being substantially free of ethylenicallyunsaturation and (B) an alcohol moiety which is the oxy residue of apolyhydric alcohol or an amino alcohol. These esters are incorporatedinto fuels and lubricants to provide the fuel and lubricatingcompositions contemplated by the invention.

The esters are readily prepared by well-known conventionalesterification procedures utilizing intermediates which are eitherreadily available commercially or easily prepared applying knowntechniques. The preparation of the esters is discussed in more detailhereinafter.

The acyl moiety of the esters is derived from a monocarboxylic acid. Oneparticularly important characteristic of the acyl moiety is its size.The radical should contain at least about fifty aliphatic carbon atomsexclusive of the carboxyl carbon atom. This limitation is based uponboth oil-solubility considerations and the effectiveness of thecompositions as additives in lubricants and fuels. Another importantaspect of the acyl radical is that it preferably should be substantiallysaturated, i.e., at least about of the total number of thecarbon-to-carbon covalent linkages therein preferably should besaturated linkages. In an especially preferred aspect of the invention,at least about 98% of these covalent linkages are saturated. Obviously,all of the covalent linkages may be saturated. A greater degree ofunsaturation renders the esters more susceptible to oxidation,degradation, and polymerization and this lessens the effectiveness ofthe final products as lubricant and fuel additives.

In addition, the acyl moiety of the esters should be substantially freefrom oil-solubilizing pendant groups, that is, groups having more thanabout six aliphatic carbon atoms. Although, some such oil-solubilizingpendant groups may be present, they preferably will not exceed one suchgroup for every twenty-five aliphatic carbon atoms in the principalhydrocarbon chain of the acyl radical.

The acyl moiety may contain polar substituents provided that the polarsubstituents are not present in proportions sufiiciently large to altersignificanly the hydrocarbon character of the moiety. Typical suitablepolar substituents are halo, such as chloro and bromo, oxo, oxy, formyl,sulfonyl, sulfinyl, thio, nitro, etc. Such polar substituents, ifpresent, preferably will not exceed 10% by Weight of the total weight ofthe hydrocarbon portion of the carboxylic acid radical exclusive of thecarboxyl group.

Monocarboxylic acid acylating agents suitable for preparing the esterscan be prepared by procedures which are well-known in the art and havebeen described for example, in U.S. Pats. 3,087,936; 3,163,603;3,172,892; 3,189,544; 3,219,666; 3, 272,746; 3,288,714; 3,306,907;3,331,776; 3,340,281; 3,341,542; and 3,346,354. In the interest ofbrevity, these patents are incorporated herein for their disclosure ofsuitable methods for preparing high molecular weight monocarboxylic acidacylating agents which can be used for preparing the esters of thepresent invention.

As disclosed in the foregoing patents, there are several processes forpreparing the monocarboxylic acid acylating agents. Generally, theprocess involves the reaction of (1) an ethlenically unsaturatedmonocarboxylic acid, acid halide, or anhydride with (2) either anethylenically unsaturated hydrocarbon containing at least about fiftyaliphatic carbon atoms or a chlorinated hydrocarbon containing at leastabout fifty aliphatic carbon atoms at a temperature within the range ofabout 100-300 C. The chlorinated hydrocarbon or ethylenicallyunsaturated hydrocarbon reactant can, of course, contain polarsubstituents, oil-solubilizing pendant groups, and be unsaturated withinthe general limitations explained herein- When preparing the carboxylicacid acylating agent according to one of these two processes, themonocarboxylic acid reactant corresponds to the general formula R COOH,where R contains up to about nine aliphatic carbon atoms and ischaracterized by the presence of at least one ethylenically unsaturatedcarbon-to-carbon covalent bond. Normally, the acids will correspond tothe formulae RCH=CH(CH ),,COH or BOH=CCOOE ,5,

where R is hydrogen or alkyl and R is hydrogen or methyl, with theproviso that R,R', and n, are such that the total number of carbon atomsin the acid does not exceed ten. The acidic reactant can also be thecorresponding carboxylic acid halide, anhydride, or other equivalentacylating agent and mixtures of one or more of these. Usually, the totalnumber of carbon atoms in the acidic reactant will not exceed six.Preferably the acidic reactant will have at least one ethylenic linkagein an 0:,5- position with respect to the carboxyl function. Exemplaryacidic reactants are acrylic acid, methacrylic acid, acryl chloride,allyl acetic acid, cinnamic acid, crotonic acid, angelic acid, tiglicacid, sorbic acid, lO-decenoic acid, and the like.

As is apparent from the foregoing discussion, the carboxylic acidacylating agents may contain cyclic and/or aromatic groups. However, theacids are essentially aliphatic in nature and in most instances, thepreferred acid acylating agents are aliphatic monocarboxylic acid,anhydrides, and halides.

The ethylenically unsaturated hydrocarbon reactant and the chlorinatedhydrocarbon reactant used in the preparation of the acylating agents areprincipally the high molecular weight, substantially saturated petroleumfractions and substantially saturated olefin polymers and thecorresponding chlorinated products. The polymers and chlorinatedpolymers derived from mono-olefins having from two to about thirtycarbon atoms are preferred. The especially useful polymers are thepolymers of I-monoolefins such as ethylene, propene, l-butene,isobutene, 1- hexene, l-octene, Z-methyl-l-heptene,3-cyclohexyl-l-butene, and Z-methyl-S-propyl-l-hexene. Polymers ofmedial olefins, i.e., ole-fins in which the olefinic linkage is not atthe terminal position, likewise are useful. These are exemplified byZ-butene, 3-pentene, and 4-octene.

. The interpolymers of l-mono-olefins such as illustrated above witheach other and with other interpolymerizable olefinic substances such asaromatic olefins, cyclic olefins, and polyolefins, are also usefulsources of the ethylenically unsaturated reactant. Such interpolymersinclude for example, those prepared by polymerizing isobutene withstyrene, isobutene with butadiene, propene with isoprene, propene withisobutene, ethylene with piperylene, isobutene with chloroprene,isobutene with p-methyl-styrene, l-hexene with 1,3-hexadiene, l-octenewith l-hexene, 1- heptene with l-pentene, 3-methyl-1-butene withl-octene, 3,3-dimethyl-l-pentene with l-hexene, isobutene with styreneand piperylene, etc.

' For reasons of oil-solubility and stability, the interpolymerscontemplated for use in preparing the acylating agents of this inventionshould be substantially aliphatic and substantially saturated, that is,they should contain at least about 80% and preferably about 95 on aweight basis, of units derived from aliphatic mono-olefins. Pref erably,they will contain no more than about 5% olefinic linkages based on thetotal number of the carbon-to-carbon covalent linkages present.

The chlorinated hydrocarbons and ethylenically unsaturated hydrocarbonsused in the preparation of the acylating agents can have molecularweights of from about 700 up to about 100,000 or even higher. Thepreferred reactants are the above described polyolefins and chlorinatedpolyolefins having an average molecular weight of about 700 to about5,000 when the acylating agent has a molecular weight in excess of about10,000, the acylated nitrogen composition also possess viscosity indeximproving qualities.

in lieu of the high molecular weight hydrocarbons and chlorinatedhydrocarbons discussed above, hydrocarbons containing activating polarsubstituents which are capable of activating the hydrocarbon molecule inrespect to reaction with an ethylenically unsaturated acid reactant maybe used in the above-illustrated reactions for preparing the acylatingagents. Such polar substituents include sulfide and disulfide linkages,and nitro, mcrcapto, carbonyl, and formyl radicals. Examples of these'polar substituted hydrocarbons include polypropene sulfide,dipolyisobutene disulfide, nitrated mineral oil, di-polyethylenesulfide, brominated polyethylene, etc.

Monocarboxylic acid acylating agents may be obtainedby oxidizing amonoalcohol with potassium permanganate or by reacting a halogenatedhigh molecular weight olefin polymer with a ketene. Another convenientmethod for preparing monocarboxylic acid involves the reaction'ofmetallic sodium with an acetoacetic ester orfa malonic ester of analkanol to form a sodium derivative of the ester and the subsequentreaction of the sodium derivative with a halogenated high molecularweight hydrocarbon such as brominated wax or brominated polyisobutene.Monocarboxylic acid acylating agents can also be ob-. tained by reactingchlorinated monocarboxylic acids, an.' hydrides, acyl halides, and thelike with ethylenically unsaturated hydrocarbons or ethylenicallyunsaturated substituted hydrocarbons such as the polyolefins andsubstituted polyolefins described hereinbefore in the manner describedin US. Pat. 3,340,281. The acid anhydrides are obtained by dehydratingthe corresponding acids. Dehydration is readily accomplished by heatingthe acid to'a temperature above about 70 C., preferably in the presenceof a dehydration agent, e.g. acetic anhydride. Acid halides of thecarboxylic acids can be prepared by the reaction of the acids or theiranhydrides with a halogenat ing agent such as phosphorus tribromide,phosphorus pentachloride, or thionyl chloride.

The esters are generally prepared by reacting the carboxylic acidacylating agent, preferably the acid per se, its acyl chloride, or ananhydride thereof, with the desired alcohol according to conventionalprocesses for preparing carboxylic acid esters. These alcoholsare eitherpolyhydric alcohols characterized by two to ten hydroxyl groups or aminoalcohols and can be quite diverse in structure and chemical composition.v

Useful polyhydric alcohols include alkylene glycols and polyoxy alkyleneglycols such as ethylene glycol, propylene glycol, trimethylene glycol,but'ylene glycol, and poly glycols such as diethylene glycol,triethylen'e -glycdLtetraethylene glycol, dipropylene glycol,tripropylene glycol,

dibutylene glycol, tributylene glycol, and other alkylene,

glycols and polyoxy alkylene glycols in which thelalkyh ene radicalcontains from 2 to about 8 carbon atoms. The monoethers of the polyoxyalkylene glycols are also useful in preparing esters of the presentinvention. These include the monoaryl ethers, monoalkyl ethers, andmonoaralkyl ethers of the formula Ho\R -o -:R,0 R; w 7 where R is arylsuch as phenyl, lower alkoxy phenyl, or lower alkyl phenyl, lower alkylsuch as ethyl, propyl, tert-butyl, pentyl, etc., and aralkyl such asbenzyl, phenyl-- ethyl, phenylpropyl, p-ethyl phenylether, etc., 11 is awhole. number of 2 to about .150, and R and R are lower alkylene of upto eight, preferably, twoto four carbon atoms.

Other useful polyhydric alcohols include glycerol, men-,- omethyl etherof glycerol, penthaerythritoh, 9,10-dihydroxystearic acid, the etherylester of 9,10-dihydroxystearic acid, 3-chloro-1,2-propanediol,1,2-butanediol, 1,4- butanediol, 2,3-hexanediol, 2,4-hexanediol,pinacoLIe-rytha ritol, arabitol, sorbitol, mannitol,1,2-cyclohexanediol,

1,4-cyclohexanediol, 1,4-(2 hydroxyethyl)-cyclohe: rane,,v

1,4-dihydroxy-2-nitro-butane, 1,4, di(2 hydroxyethyl) benzene, thecarbohydrates suchas glucose, .ramnOSfir mannose, glyceraldehyde, andgalactose, di(2-hyd roxyethyl)amine, tri-(3-hydroxypropyl)amine, N,'Ndi( hy- .5 droxy ethyl) ethylenediamine, copolymer of allyl alcohol andstyrene, etc.

Included within this group of aliphatic alcohols are those polyhydricalcohols containing at least three hydroxyl groups, at least one ofwhich has been esterified with a monocarboxylic acid having from eightto about thirty carbon atoms such as octanoic acid, oleic acid, stearicacid, linoleic acid, dodecanoic acid, or tall oil acid. Examples of suchpartially esterified polyhydric alcohols are the mono-oleate ofsorbitol, sorbitan monooleate, the mono-oleante of glycerol, themono-stearate of glycerol, the di-stearate of sorbitol, and thedi-dodecanoate of erythritol.

A preferred class of esters are those prepared from polyhydric alcoholscontaining up to ten carbon atoms, and especially those containing threeto ten carbon atoms. This class of alcohols includes glycerol,erythritol, pentaerythritol, gluconic acid, glyceraldehyde, glucose,arabinose, 1,7-heptanediol, 2,4-heptanediol, 1,2,3-hexanetriol,1,2,4-hexanetriol, 1,2,5-hexanetriol, 2,34-hexanetriol, 1,2,3butanetriol, 1,2,4 butanetriol quinoic acid, 2,2,6,6 tetrakis(hydroxymethyl) cyclohexanol, 1,10- decanediol, digitalose, and thelike. The esters prepared from aliphatic alcohols containing at leastthree hydroxyl groups and up to ten carbon atoms are particularlypreferred.

An especially preferred class of polyhydric alcohols for preparing theesters used as starting materials in the present invention are thepolyhydric alkanols containing three to ten carbon atoms andparticularly, those containing three to six carbon atoms and having atleast three hydroxy groups. Such alcohols are exemplified in the abovespecifically identified alcohols and are represented by glycerol,erythritol, pentaerythritol, mannitol, sorbitol, 1,2,4-hexanetriol, andthe like.

The amino alcohols contemplated as suitable for preparting the esterscan be monohydric or polyhydric. Examples of suitable amino alcohols arethe N-hydroxy lower alkyl amines and poly amines such as2-hydroxyethylamine,

3-hydroxybutylamine,

di- (2-hydroxyl ethyl) amine,

tri- (Z-hydroxyethyl amine,

di: (2-hydroxypropyl) amine,

N,N,N-tri- Z-hydroxyethyl) ethylenediamine, N,N,N',N-tetra-(2-hydroxyethyl ethylenediamine, N- (2-hydroxyethyl -piperazine,

N,N-di- 3-hydroxypropyl piperazine,

N- (2-hydroxyethyl) morpholine,

N Z-hydroxyethyl -2-morpholinone,

N- (Z-hydroxyethyl) -3-methyl-2-morpholinone,

N- 2-hydroxypropyl) -6-methyl-2-morpholinone, N- Z-hydroxyethyl--carbethoxy-2-piperidone,

N- 2-hydroxypropyl) -5-carbethoxy-Z-piperidone, N- (Z-hydroxyethyl -5-(N-butylcarbamyl -2-piperidone, N- (2-hydroxyethyl piperidine,

N- 4-hydroxybutyl piperidine,

N,N-di- (2-hydroxyethyl glycine,

and esters thereof with aliphatic alcohols, especially lower alkanols,N,N-di(3 hydroxypropy'l)'glycine, and the like. Also contemplated areother monoand poly-N-hydroxyalkyl-substituted alkylene polyamineswherein thhe alkylene radicals contain two to four carbon atoms and thepolyamine has up to seven amino groups.

As mentioned above, the esters are prepared by mixing the alcohol andcarboxylic acid acylating agent at a temperature of about 100 C. orhigher and usually at 150"- 300" C. The reaction is usually conducted inthe presence of a substantially inert organic diluent. Suitable diluentsinclude the aliphatic, cycloaliphatic, and aromatic hydrocarbons andtheir chlorinated analogs exemplified by pentane, hexane, heptane,cyclohexane, benzene, toluene, xylene, chlorobenzene, chlorohexanes, andthe like. Mineral oils, naphthas, ligroin, and the like may also be usedas a diluent. The diluent is preferably selected so no solubilityproblems will arise when the ester solution thus prepared are added tothe fuel or lubricant. That is, it is desirable to prepare the ester ina diluent which is soluble in the fuel or lubricant in which it is to beused. Lowviscosity mineral oil is a particularly useful diluent, eitheralone or in combination with other diluents.

The reaction mixture comprises at least one rnonocarboxylic acidacylating agent and at least one alcohol. That is the ester compositionscontemplated by the present invention include mixtures of estersprepared by reacting one or more different monocarboxylic acid acylatingagents with one or more different alcohols of the general type describedhereinabove. Or, the ester mixtures can be prepared by mixing two ormore individually prepared esters.

The stoichiometry of the reaction requires at least one equivalent ofalcohol for each equivalent of acylating agent. The acylating agentshave one equivalent per mole while the number of equivalents of analcohol per mole depends upon the number of free alcoholic hydroxygroups present therein. Thus, g ycerol has three equivalents per mole;pentaerythritol, four; tri-(2-hydroxyethyl)amine,

three; polyoxyethyleneglycol, two; etc. Ordinarily, the total amount ofacylating agent and alcohol used in the reaction mixture will vary froma ratio of about 1:1 moles to about 1:1 equivalents.

As is apparent to those skilled in the art, it is possible for up to onemole of monocarboxylic acid acylating agent to combine with each treealcoholic hydroxyl group present. Accordingly, the esters of theinvention include polyesterified polyhydric alcohols. Where aminoalcohols are used, it is possible that some of the acylating agents willreact with primary or secondary amino groups. Compounds characterized bya group resulting from the reaction of the acylating agent with an aminogroup, e.g., an amide group, are not included within the scope of thepresent invention. Only those esters free from such groups arecontemplated by the present invention.

The following exampes illustrate preferred embodiments of thisinvention. As used in these exampes and elsewhere in the specificationand claims, percentage, and parts refer to percent by weight and partsby weight unless otherwise indicated.

EXAMPLE 1 A carboxylic acid ester is prepared by slowly adding 3240parts of a high molecular weight carboxylic acid (prepared by reactingchlorinated polyisobutylene and acrylic acid in a 1:1 equivalent ratioand having an average molecular weight of 982) to a mixture of 200 partsof sorbitol and 1000 parts of diluent oil over a 15-hour period whilemaintaining a temperature of 1l5-125 C. Then 400 parts of additionaldiluent oil are added and the mixture is maintained at about 195-205 C.for 16 hours while blowing the mixture with nitrogen. An additional 755parts of oil are then added, the mixture cooled to C., and filtered. Thefiltrate is an oil solution of the desired ester.

EXAMPLE 2 An ester is prepared by heating 658 parts of a carboxylic acidhaving an average molecular weight of 1018 (prepared by reactingchlorinated polyisob-utene with acrylic acid) with 22 parts ofpentaerythritol while maintaining a temperature of about -205 C. forabout 18 hours during which time nitrogen is blown through the mixture.The mixture is then filtered and the filtrate is the desired ester.

EXAMPLE 3 To a mixture comprising 408 parts of pentaerythritol and 1100parts oil heated to 120 C., there is slowly added 2946 parts of the acidof Example 1 which has been preheated to 120 C., 225 parts of xylene,and 95 parts of diethylene glycol dimethylether. The resulting mixtureis 7 heated at 195 "-205 C., under a nitrogen atmosphere and refluxconditions for eleven hours, stripped to 140 C. at 22 mm. (Hg) pressure,and filtered. The filtrate comprises the desired ester. It is diluted toa total oil content of 40%.

EXAMPLE 4 (A) An ester is prepared following the general procedure ofExample 1 by reacting 1 equivalent of a carboxylic acid chloride(prepared by reacting 1 mole of polyisobutene (average molecularweight-4500) with 2.5 moles of chloroacetyl chloride according to US.Pat. 3,340,281 and thereafter removing excess ehloroacetyl chloride)with 3 equivalents of mannitol. After filtration, the filtrate isdiluted to a mineral oil content of 40%.

(B) The procedure of Example 4(A) is repeated but the acid chloride isreplaced with 1 equivalent of an acid chloride prepared by reacting anisobutylenezpropylene copolymer (average molecular weight2200)containing about 20% propylene units and chloroacetylchloride in a molarratio of coplymer to chloroacetylchloride of 122.5 following theprocedure of Pat. 3,340,281.

Following the general procedure of Example 1, esters are prepared fromthe acylating agents and alcohols indicated in the following table inthe equivalent ratio shown. Obviously, more or less diluent can be usedas desired to facilitate handling, etc. By substituting other acylatingagents and alcohols of the types discussed and exemplified hereinabovefor those of the table or foregoing examples, still other esters of thetype contemplated by the present invention can be prepared readily.

TABLE Acrylating Equivalent agent ratio of Ex. (X) Alcohol (Y) (X): (Y)

5--- A Ptixl lygilryetiiylene glycol (average 1:1 8.-- A Pcl ldygvxypropylene glycol (average 1. 5:2 7-..... A Polyoxypropylene glycol(average 1:2

M.W. 1,025). 8..-..- B Glycerol 2:3 9 A Di-(Z-hydroxyethyl) amino... :110.--. A Sorbitan mono-oleate 1:1 11---- Moiiopllienyl ether oftrioxypropylene 1:1

g yco 12---- A Monoethyl ether of polyoxyethylene 1:1

glycol (average M.W. 13O). 13..-- A 1,4-di-(2-hydroxyethyl) piperazine1:1 Mannitol 1:2 15. A Monobenzyl ether of polyoxypropylene 1:1

glycol (average M.W. 510). 16- A N-(Z-hydroxyethyl) morpholine 1 1 17- AN,N-di (Z-hydroxyethyl) ethylene 1 :1

diamine. 18- A N,N-di-(2 hydroxyethyl) glycine 1:2

Nora

A=hcrylating agent of Example 1. B=Aerylat1ng agent of Example 4(A).C=Aerylating agent of Example 4(B);

As mentioned before, the esters of this invention are useful asadditives in lubricants and fuels. When employed as lubricating oiladditives they are usually present in amounts of from about 0.01% toabout 30% by Weight in the final lubricating composition. Ordinarily,when used as additives for lubricating oil compositions, the esters willbe present in amounts of from about 0.5% to about by weight althoughunder unusually adverse conditions, such as in the operation of certaindiesels, they may comprise up to about 30% by weight of the lubricant.The products are particularly useful as dispersants in lubricating oilcompositions used in the crankcase of various internal combustionengines. Although they can be used effectively in gear and transmissionlubricants, hydraulic fluids and the like. When employed in lubricatingoils, the esters may be used alone or in combination with otherdispersants or detergents. In addition, the lubrieating composition maycontain rust inhibitors, oxidation inhibitors, viscosity index improvingagents, extreme pressure additives, and the like. Typical examples ofthese additional additives are contained in the above-identified patentsdisclosing the carboxylic acid acylating agents useful in preparing theesters of the present invention.

The additives of this invention can be effectively employecl in avariety of lubricating compositions based on natural or syntheticlubricating oils or on combinations of miscible or mutually solublenatural and synthetic oils. The term miscible is intended to describethe situation where the oils are soluble in each other whereas theterminology mutually soluble is intended to describe a situation where asuitable common solvent, perhaps another lubricating oil, permits theuse of two or more lubrieating oils in combination where they would nototherwise normally be satisfactory for a combination use due tosolubility problems. The lubricating compositions contemplated areprincipally lubricating oils for both sparkignition andcompression-ignition internal combustion engines. However, otherlubricating compositions can benefit from the incorporation of theseadditives including lubricants for automatic transmissions, gearlubricants, metal-working lubricants, and hydraulic fluids. While theabove lubricating compositions are normally liquids. it is alsoanticipated that they may be converted to thickened lubricants orgreases for specific applications by application of conventionalgrease-forming procedures without departing from the scope of thisinvention.

Natural oils include castor oil, lard oil, and solventrefined oracid-refined mineral lubricating oils of the parafiinic, naphthenic, ormixed paraffinic-naphthenic aypes. Oils of lubricating viscosity derivedfrom coal or shale are also useful base oils. Other syntheticlubricating oils include hydrocarbon oils such as polymerized olefins(e.g., polybutylenes, polypropylenes, etc.); alkyl benzenes (e.g.,dodecyl benzenes, tetardecyl benzenes, dinonyl benzenes,di-(Z-ethylhexyl) benzenes, etc.); polyphenyls (e.g., biphenyls,terphenyls, etc.); and the like. Alkylene oxide polymers and derivativesthereof where the terminal hydroxyl groups have been modified byesterification. etherification, etc, constitute another class of knownsynthetic lubricating oils. These are exemplified by the oils preparedthrough polymerization of propylene oxide, the alkyl and aryl ethers ofthese polyoxyalkylene polymers (e.g., methylpolyisopropylene etherhaving an average molecular weight of 1000, diphenylether ofpolyethylene glycol having a molecular weight of 500-1000, diethyl-etherof polypropylene glycol having a molecular weight of 1000-1500, etc.)orthe lower alkanoyl esters thereof such as the acetic esters. Anothersuitable class of synthetic lubricating oils comprises the esters ofdicarboxylic acids (e.g., phthalic acids, succinic acid, maleic acid,azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid,etc.) with a variety of alcohols (e.g., butyl alcohol, hexyl alcohol,dodecyl alcohol, 2- ethylhexyl alcohol, etc.). Specific examples ofthese include dibutyl adipate, di-(2 ethylhexyl)sebacate, di-nhexylfumarate, dioctyl sebamte, diisoocyl azelate, di octylphthalate, didecylphthalate, dieicosyl sebacate,and the like. Other synthetic lubricatingoils include liquid esters of phosphorus-containing acids (e.g.,tricresyl phosphate, diethyl ester of decane phosphonic acid, etc.),alkyl diphenyl ethers; and polymerized tetrahydrofuranes. Silicone-basedoils such as the polyalkyl-, polyaryl-, polyalkoxy-, andpolyaryloxy-siloxane oils and silicate oils comprise another usefulclass of synthetic lubricants (e.g., tetraethyl silicate, tctraisopropylsilicate, tetra-2.- ethylhexyl silicate, tetra(4-methyl-2-tetraethyl)silicate, tetra-p-tert-butylphenyl silicate, hexyl(4-methyl-2-pentoxy)disiloxane, poly(methyl)siloxanes,poly(methylphenyl)-siloxanes, etc.). This identification of certain oilsis not intended to be inclusive but is merely illustrative of the typeof base oils contemplated by this invention.

In fuels, the esters, promote engine cleanliness by re-. ducing oreliminating harmful deposits in the fuel systern, engine, and exhaustsystem. Their-presence promotes carburetor and fuel line cleanliness andreduces or elimie nates the deposition of carbonaceous deposits ininternal 9. parts of the engine such as on-exhaust parts. Normally, theesters used in-fuels will be derived from acids having an averagemolecular weight of about 700-2000 and alcohols containing not more thanabout ten carbon atoms. The esters are primarily intended for use in thenormally liquid petroleum distillate fuels, that is, the petroleumdistillates which-boil in the range characteristic of petroleum fuelssuch as gasolines, fuel oils, diesel fuels, a'viation' fuels,"kerosene,and the like. When employed in fuels, they aregenerally employed inlower concentrations than in'lubricants, for example, in amounts of fromabout 0.001% to about 2% by weight and generally in amounts of fromabout 0.01% to about 1% by weight. As in the case of lubricants, otherconventional additives-can be present in the fuel compositionscontemplated by the present invention. Additional additives include leadscavengers, deicers, antiscreen clogging agents, demulsifiers, smokesuppressants and the like. The following are examples of the lubricatingand fuel compositions contemplated by the present invention.

EXAMPLE A SAE 30 mineral oil containing 1% of the product of Example 1and 0.5% of the product of Example 8.

' EXAMPLE B SAE 20 mineral oil containing 0.75 of the product of Example2 and 0.15% of the zinc salt of an equimolar mixture ofdi-cyclohexylphosphorodithioic acid and diisobutylphosphorodithioicacid.

EXAMPLE C SAE lW-30 mineral lubricating oil containing 4% of the productof Example 3.

EXAMPLE D EXAMPLE E SAE 20 mineral lubricating oil containing 2.5% ofthe product of Example 18, 0.75% of phosphorus as thedioctylphosphorodithioate, 2% of a barium detergent prepared byneutralizing with barium hydroxide a hydrolyzed reaction product of apropylene (molecular weight 2000) with one mole of phosphoruspentasulfide and one mole of sulfur, 3% of a barium sulfonate detergentprepared by carbonating a mineral oil solution of mahogany acid and a'5% stoichiometrically excess amount of barium hydroxide in the presenceof octylphenol as the promoter at 180 C., 3% of a supplemental ashlessdispersant prepared by copolymerizing a mixture of 95% by weight ofdecylmethacrylate, 5% by weight of diethylaminoethyl acrylate.

EXAMPLE F A di-Z-ethylhexyl sebacate lubricating composition compresing0.75 of the product of Example 8.

EXAMPLE G Diesel fuel containing 0.2% of the product of Example 17.

EXAMPLE H Kerosene containing 0.15% of the product of Example 9.

10 EXAMPLE I Gasoline containing 0.007% of the product of Example 16.

The foregoing compositions illustrate types of compositions contemplatedby the present invention. Many additional compositions apparent to thoseskilled in the art are avaliable simply by replacing all or part of theesters used in these fuels and lubricants with an equal amount of otheresters of the present invention. Obviously, optimum amounts for anyapplication will depend upon the particular additive or additivecombination selected, the specific fuel or lubricant, and the specificenvironment in which the fuel or lubricant is to be used. These optimumamounts can be ascertained through conventional evaluation techniquescommonplace in the industry.

As is apparent to those skilled in the art, the terminology carboxylicacid moiety and acyl residue of a monocarboxylic acid as used in thespecification and claims is intended to describe the carboxylic acidacyl radical of the esters of the invention, (e.g.,

where R, contains at least about fifty aliphatic carbon atoms).Similarly, alcoholic moiety and oxy residue are intended to describe thealcohol radical of the ester, that is, the oxy radical corresponding tothe esterfied alcohol absent one or more hydrogens from alcoholichydroxyl groups (e.g., OCH CHOHCH O,

OCHCH N CH CH OH etc.).

What is claimed is:

1. An oil-soluble ester of a high molecular weight substantially,saturated hydrocarbon monocarboxylic acid and an alcohol, wherein thecarboxylic acid moiety is the acyl residue of a hydrocarbonmonocarboxylic acid having at least 50 aliphatic carbon atoms in thehydrocarbon portion, and the hydrocarbon portion may contain polarsubstituents in an amount up to about 10 by weight of the hydrocarbonproportion exclusive of the carboxy group; and the alcohol moiety is theoxy residue of an alcohol selected from the group consisting ofpolyhydric alcohol having from 2 to about 10 hydroxy groups or an aminoalcohol.

2. The oil-soluble ester of claim I, wherein the hydrocarbon portion ofthe monocarboxylic acid has an average molecular weight of from about700 to about 5000, and the alcohol moiety contains up to about 40aliphatic carbon atoms.

3. The oil-soluble ester of claim 2, wherein the alcohol moiety is anoxy residue of a polyhydric amino alcohol.

4. The oil-soluble ester of claim 2, wherein the alcohol moiety is theoxy residue of a polyhydric alkanol containing 3 to 10 aliphatic carbonatoms.

5. The oil-soluble ester of claim 2, wherein the alcohol moiety is anoxy residue of a polyhydric alkanol containing up to 10 aliphatic carbonatoms, and at least three hydroxy groups.

6. The oil-soluble ester of claim 1, wherein the hydrocarbonmonocarboxylic acid was prepared by the reaction of a l-monoolefinpolymer of a chlorinated l-monoolefin polymer with an a,fl-ethylenicallyunsaturated monocarboxylic acid containing up to 6 carbon atoms, and thehydrocarbon portion of the monocarboxylic acid is substantially free ofethylenic unsaturation and has an average molecular weight'of from about700 to about 5000.

7. Thes oil-soluble ester of claim 6, wherein the alcohol moiety is anoxy residue of a polyhydric alkanol containing at least 3 hydroxy groupsand 3 to 6 carbon atoms.

8. The oil-soluble ester of claim 7, wherein the alcohol moiety is anoxy residue of a polyhydric alkanol selected from the class consistingof glycerol, erythritol, pentaery thritol, sorbitol, and mannitol.

9. The oil-soluble ester of claim 6, wherein the alcohol moiety is anoxy residue of an N-hydroxy alkyl amine.

10. The oil-soluble ester of claim 9, wherein the alcohol moiety is anoxy residue of an N-hydroxyalkyl monoamine.

11. The oil-soluble ester of claim 9, wherein the alcohol moiety is anoxy residue of an N-hydroxyalkylalkylene-polyamine having up to 4 carbonatoms in the alkylene group and up to 7 amino groups.

12. An oil-soluble ester of a high molecular weight substantiallysaturated aliphatic hydrocarbon monocarboxylic acid and an alcohol,wherein the carboxylic acid moiety is the acyl residue of a hydrocarbonmonocarboxylic acid having an average molecular weight of from about 700to about 5000, exclusive of the carbonyl group, and the hydrocarbonportion may contain polar substituents in an amount up to about byweight of the hydrocarbon portion exclusive of the carbonyl group; andthe alcohol moiety is an oxy residue of an alcohol selected from theclass consisting of polyoxyalkylene glycols having up to 150 oxyalkylenegroups, and the mono-aryl-, mono-alkyl-, or mono-aryl-alkyl-ethers ofthe polyoxyalkylene glycols.

13. The oil-soluble ester of claim 12, wherein the alcohol moiety is anoxy residue of the polyoxyalkylene glycols.

14. The oil-soluble ester of claim 12, wherein the hydrocarbonmonocarboxylic acid was prepared by the reaction of a l-monoolefinpolymer of a chlorinated 1- monoolefin polymer with ana,;3-ethylenically unsaturated monocarboxylic acid containing up to 6carbon atoms.

15. An oil-soluble ester of a high molecular weight substantiallysaturated hydrocarbon monocarboxylic acid and a polyhydric alcohol,wherein the hydrocarbon monocarboxylic acid moiety is the acyl residueof the acid prepared by the reaction of a polyisobutylene or a chlori-References Cited ifi. f, L; UNITED STATES PATENTS 3,451,931 6/1969 Kahnof a1. 252- 32 7- 3,452,002 6/1969 Brasch t 260, 239,3 2,433,016 12/1947Coffman 260/413 3,049,557 8/1962 Emrick 4106 3,255,108 6/1966 Wiese 25232 .7, 3,381,022 4/1968 -Le Suer 260 -4043 3,272,746 9/ 19 66 Le Suereta1.-- 252e 47.5 3,341,542 9/1967 Le Suer et al 260 268 2,138,77111/1938" Pevcl'e" l 260-4106 X 2,238,478 4/ 1941 Bohner et al., 1.Chemical & Engineering Data vol. 7, No. 4, pp. 547-553 (1962).-

LEWIS oo'r'rs, Primary Examinerilji r D. G. RIVERS, Assistant Examiner;

. U.S. Cl. X.R. w

260-234 R, 247.2 B, 268 R, 293.88, 399, 400, -4i)4,"4"ois*j 410, 410.5,410.6, 410.7

UNITED STATES PATENT OFFICE CERTIFICATE OF- CORRECTION Patent No.3855624 I Dated September 3, 97

Inventor(s) John B rk It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

At column 10, line 61, that is Claim 6, line 5, "of

second occurrence should be 'or--; at column 10, line 8, that is Claim7, line l, "Thee" firstv occurrence should be At column ll, line 29,that is Claim 1 line 5, "of" second occurrence should be --or-.

Signed and sealed this 3rd day of December 1974.

(SEAL) Attest:

MCCOY 'M. GIBSON JR.- Attesting Officer c. MARSHALL DANN Commissioner ofPatents FORM po'wso (10'69) I uscoMM-Dc soars-Poo U.S. GOVERNMENTPRINTHIG OFFICE 2 ll, O3-33l.

